Seminar - Mechanics of Soft Materials-Large Deformation Kinetics of Hydrogels and Predicting Mechanical and Physical Properties of Silica Aerogels using Molecular Dynamics Simulations and Analytical Approach by Prof. Zishun Liu
Date: 27 March 2014 (Thursday)
Time: 11:00 am - 12:00 pm
Venue:EF305, The Hong Kong Polytechnic University
The growing number of possible applications of soft matter such as hydrogels has generated significant interest in developing a deeper understanding of these materials’ mechanical behavior. Non-linear large deformation study of soft material, such as hydrogels, is a new research topic, as the potential application of this soft material in emerging new technology. To accurately design new soft machines, it is imperative to understand the non-linear large deformation kinetics of polymeric gel. This can be achieved through the use of finite element modeling of the material properties. In this presentation, the transient swelling process of polymeric gels and numerical implementation for large deformation kinetics of polymeric gels using finite element method will be presented. The neutral and environmental sensitive hydrogels are investigated. For temperature sensitive hydrogels, by analyzing the factors affecting the phase transition temperature of hydrogel, we propose one possible chemical mechanism for the swelling behavior of temperature-sensitive gel during the phase transition process. For verification purpose, a few typical examples which can represent the kinetic deformation phenomena are modeled and simulated using developed subroutine or code. I will adopt the simulation method to explain some natural phenomena, such as plant growing and drying process, swelling-induced bifurcation, buckling of skin of human hand. I also hope that our work can provides a useful tool for the future theoretical and experimental studies of soft material. Furthermore, the mechanical properties of aerogels which is the lightest solid material, are characterized and predicted through numerical and theoretical approaches.
Dr. Zishun Liu is a SANQIN Chair Professor of Xi’an Jiaotong University (XJTU) and Executive Director of International Center for Applied Mechanics. Dr. Liu received B.Eng., M.Eng. degrees in Applied Mechanics and Solid Mechanics from XJTU, and M.Eng., Ph.D. degrees in Solid Mechanics from the National University of Singapore (NUS). He served on the faculty of XJTU between 1986 and 1994, and as Senior Scientist, Scientist, Senior Research Engineer, Capability Group Manager, Team Leader at Institute of High Performance Computing, Singapore (IHPC), and Associate Professor of NUS at various points from 1999 to 2012. Dr Liu had also taken up leadership positions at IHPC being the Manager of Soft Matter Capability Group, the Assistant Programme Manager of Solid Mechanics and the team leader of Engineering Mechanics in his career. As a visiting scientist, he worked in Max Planck Institute for Metals Research, Stuttgart, Germany and University of Glasgow, UK. in 2005 and 2006 respectively. Now he holds Adjunct Professorships in NUS and IHPC. He is also the President of Singapore Association of Computational Mechanics. His research interests are in the areas of Mechanics of Soft Materials, Computational Solid Mechanics & Biomechanics, Nanomechanics, Vibro-Acoustic. He has published over 100 scientific publications. He has given many invitation talks in USA, UK, China, Canada, Japan, Czech and Singapore Universities, Research Institutes. Dr Liu is an active member of various leadership roles in editorial boards and professional communities as follow: Dr. Liu is an Editor-In-Chief of Int. Journal of Applied Mechanics (IJAM) and Editor-In-Chief of Int. Journal of Computational Materials Science and Engineering (IJCMSE), as well as serves on a few editorial boards, including Editor of Int. Journal of Aerospace and Lightweight Structures (IJALS); Editorial board member of Int. Journal of Computational Method; Guest editor of Computational Materials Science; Editorial board member of Chinese Journal of Applied Mechanics; Editorial board member of Multidisciplinary Modeling in Materials and Structures; General Committee Member of Association of Asia-Pacific Computational Mechanics (APACM) ; Executive Committee Member of Theoretical and Applied Mechanics Society of Singapore; Executive Committee Member of Materials Research Society of Singapore; Members of the International Union of Materials Research (IUMR); Member of the International Association for Computational Mechanics (IACM).